Computer use such as surfing the World Wide Web or Internet may be hazardous as criminals have infested it by malicious software (malware) including computer viruses, worms, Trojan horses, spyware, adware, rootkits, ransomware and other malicious programs. Download control is crucial in avoiding damage caused by the malware. However, criminals move fast, and antivirus software may not always recognize suspicious web sites. Consequently, further sophistication is desirable for recognizing dangerous situations.